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<3^- 


THE 

UNIVERSITY  OF  MISSOURI 
BULLETIN 


ENGINEERING  EXPERIMENT  STATION  SERIES 

VOLUME  1 NUMBER  3 


SANITATION  AND  SEWAGE  DISPOSAL 
FOR  COUNTRY  HOMES 

BY 

William  C.  Davidson 


T»cni5 


UNIVERSITY  OF  MISSOURI 
COLUMBIA,  MISSOURI. 
September,  1910 


CONTENTS. 


Page 

Introduction  

DRY  SEWAGE  METHODS. 

Waste  Matter,  Sewage  Defined 57 

The  Privy  Vault  57 

Water  Supply  Contamination 5g 

Privy  Vault  Dangers 5g 

Earth  Closets  5g 

A CONCRETE  SLOP  WATER  DISPOSAL  BASIN. 

The  Tank,  its  Use 59 

Drawings  59 

Construction  59 

Disposal  of  the  Outflow g9 

Subsurface  Disposal  of  the  Waste 60 

Approximate  Cost  61 

CESSPOOLS. 

Cesspools  61 

Leaching  Cesspools  61 

Water-Tight  Cesspools  61 

Dangers  of  Cesspools  61 

THE  SEPTIC  TANK. 

Septic  Tank  Defined 62 

Septic  Tank  Effluents 62 

Operation  of  Septic  Tanks 62 

Capacity  of  Septic  Tanks 62 

Open  and  Closed  Septic  Tanks 62 

Small  Concrete  Septic  Tank 62 

Family  of  Six  Provided  for 62 

Drawings  Showing  Tank 63 

Cost  64 

SUBSURFACE  DISPOSAL  OP  SEWAGE. 

General  Remarks  on  Subsurface  Disposal 64 

Design  of  the  Subsurface  Disposal  Plant 63 

Construction  65 

The  Septic  Tank  65 

Cost  65 

SURFACE  DISPOSAL  OF  SEWAGE. 

The  Disposal  Field 66 

Drawings  Showing  the  Plant 66 

Distributing  Ditches  66 

Cost  66 

DIRECT  DISPOSAL  INTO  RUNNING  STREAMS. 

Drawings  Showing  Plant  66 

Description  66 

Estimating  Cost  67 

COUNTRY  PLUMBING. 

A Vented  Plumbing  System 6S 

Drawings  Showing  System 69 

Cost  


SANITATION  AND 


//)  Or  if  . *4, 

1 1]  ^ «£**  o £\ 

SEWAGE  DISPOSAL  FOR  COUNTRY  HOMES. 


Introduction. — The  demand  for  modernly  equipped  farm  homes  at  a 
moderate  cost  is  becoming  an  urgent  one.  Farmers  throughout  Missouri 
are  striving  to  keep  abreast  of  the  times  in  modern  methods  of  agriculture. 
Likewise  they  are  seeking  the  latest  and  best  practices  in  every  line  of 
activity  pertaining  to  the  industry  of  farming. 

They  are  demanding  that  their  homes  be  equipped  with  the  same 
modern  conveniences  that  the  people  of  the  city  enjoy,  and  it  is  the  call 
from  them  for  information  on  modern  farm  sanitation  that  has  led  to  the 
publication  of  this  bulletin. 

The  greater  part  of  the  bulletin  is  devoted  to  the  subject  of  modern 
sewage  disposal  plants  for  isloated  houses.  A portion  has  been  given  to 
the  discussion  of  sewage  disposal  methods  now  employed  on  the  farm,  and 
still  another  portion  to  country  plumbing. 

It  is  the  purpose  of  this  bulletin  to  present  several  specific  designs 
and  to  call  attention  to  the  necessity  of  home  sanitation  in  a general  way. 

Sewage  Defined. — Sewage  is  composed  of  the  liquid  and  solid  waste 
matter  that  flows  through  a sewer.  The  character  of  the  foul  matters  thus 
carried  off  may  be  fecal,  excretory,  or  of  the  nature  of  slop  water. 

The  term  as  defined  here  may  allude  to  the  contents  of  the  privy  vault, 
dry  earth  closet,  slop  water  basin,  cesspool  or  the  septic  tank.  Sewage 
may  mean  the  contents  of  the  cesspool,  septic  tank,  etc.,  or  it  may  refer 
to  the  waste  material  after  its  final  deposit  in  a stream,  ditch  or  upon  a 
field.  The  term  generally  applied  to  sewage  as  it  flows  from  the  sewer 
to  the  final  place  of  disposal  is  effluent,  and  should  this  word  be  found  in 
subsequent  pages  of  this  bulletin  it  will  be  thus  defined. 

METHODS  OF  DISPOSAL. 

The  methods  of  sewage  disposal  may  be  conveniently  divided  into  two 
general  classes,  namely:  Water-Carriage  Systems  and  Dry  Sewage  Sys- 

tems. The  latter  will  be  taken  up  and  discussed  first,  inasmuch  as  it  is 
the  one  in  more  general  use  at  the  present  time  in  rural  communities. 

Dry  Sewage  Methods. 

Under  this  head  two  subdivisions  of  the  subject  will  be  made.  They 
are  privy  vaults  and  earth  closets.  Both  of  these  methods,  though  crude, 
can  be  made  healthful  and  sanitary  if  proper  care  is  taken  in  regard  to 
their  arrangement,  location,  and  operation. 

The  Privy  Vault. — The  privy  vault  is  the  method  most  commonly  used 
at  the  country  home.  This  system  will  continue  to  be  used  for  a long 
time  on  account  of  its  cheapness  and  economy.  Some  suggestions  are 
offered  by  which  its  sanitary  conditions  may  be  improved. 

The  privy  vault  as  ordinarily  constructed  consists  of  a small  frame 
building  erected  over  a pit  which  receives  the  refuse  or  fecal  matter.  For 
a time  such  a receptacle  is  satisfactory,  but  unless  properly  cared  for  it 
becomes  a nuisance,  obnoxious  both  to  sight  and  smell,  as  well  as  a menace 
to  health.  This  obnoxious  condition  of  privies  can  be  avoided  by  a gen- 
erous use  of  lime  and  an  occasional  removal  of  the  waste  from  the  pit. 

(57) 


T n V7  5~ 


58  Missouri  Engineering  Experiment  Station,  Bulletin  3. 

Water  Supply  Contamination. — Occasionally  a privy  ..vault  will  be  found 
near  a well,  cistern,  or  other  source  of  water  supply.  This  may  become 
polluted,  due  to  the  seepage  of  the  sewage  through  the  ground.  Further- 
more this  sewage  waste  may  be  so  clarified  by  passing  through  the  porous 
earth  that  by  the  time  it  reaches  the  neighboring  source  of  water  supply 
it  will  be  clear  and  apparently  pure.  Expericence  has  taught  us,  however, 
that  this  water  often  contains  disease  germs  which  we  have  no  means  of 
detecting  until  we  have  been  poisoned  by  them  and  have  perhaps  de- 
veloped a case  of  serious  illness. 

Privy  Vault  Dangers. — Two  of  the  common  causes  of  the  spread  of 
typhoid  fever  are  the  contamination  of  the  water  supply,  and  the  trans- 
mission of  the  disease  by  the  ordinary  house-fly.  Instance  after  instance 
could  be  given  where  cases  and  even  epidemics  of  typhoid  fever  have  been 
caused  by  the  pollution  of  wells  or  cisterns  from  neighboring  privies  which 
in  some  cases  were  located  several  hundred  feet  distant.  The  water  in 
the  wells  was  apparently  pure  and  sparkling,  yet  it  contained  the  germs 
of  disease.  Frequently  a well  or  spring  is  polluted  from  a nearby  brook 
or  gully  leading  from  a neighboring  farm  where  recently  there  may  have 
been  a typhoid  patient.  Instances  are  on  record  where  typhoid  bacteria 
were  transmitted  a mile  or  two  by  this  method.  Hence  too  much  precau- 
tion cannot  be  taken  in  the  protection  of  the  home  water  supply. 

The  privy  vault  often  becomes  a fly  breeding  place,  and  should  there- 
fore be  as  far  as  possible  from  the  house.  That  flies  do  transmit  disease, 
notably  typhoid  fever,  there  is  no  longer  any  doubt,  and  the  privy  vault 
should,  as  far  as  possible,  be  inaccessible  to  them.  This  may  be  accom- 
plished by  the  use  of  screens.  Another  effective  and  inexpensive  remedy 
for  keeping  the  flies  away  from  the  closet  is  by  a generous  use  of  dry 
air-slaked  lime  applied  daily. 

Some  precautions  should  be  observed  in  connection  with  the  building 
of  privy  vaults.  Generally  they  should  not  be  within  one  hundred  feet  of 
any  source  of  water  supply.  Do  not  leave  the  excreta  accessible  to  flies. 
Do  not  neglect  the  frequent  removal  of  the  waste  material  from  the  vault. 
If  possible  select  the  location  of  the  privy  vault  so  that  the  liquid  waste 
will  drain  away  from  the  premises  into  a ditch  or  gully  rather  than  to 
have  it  pass  near  the  cistern. 

Earth  Closets. — In  connection  with  dry  sewage  systems  we  have  the 
earth  closet  which  is  perhaps  little  used  in  this  country,  although  employed 
to  quite  an  extent  in  England.  The  earth  closet  is  simple  and  cleanly  and 
in  many  respects  an  entirely  satisfactory  substitute  for  the  privy. 

The  excreta  should  be  received  in  a box  or  pail  made  to  fit  closely 
beneath  the  seat.  The  seat  may  be  like  that  of  an  ordinary  water  closet. 
Each  time  the  closet  is  used  a small  amount  of  dry  earth  is  added.  The 
action  of  dry  earth  is  to  deordorize  and  render  harmless  the  waste  matter 
of  the  closet.  The  receptacle  should  be  emptied  frequently.  The  out-house 
or  closet  should  be  well  lighted  and  ventilated,  and  preferably  plastered 
on  the  inside.  With  proper  attention,  this  closet  need  not  be  built  far  from 
the  dwelling  house. 

The  earth  used  in  such  a closet  should  be  dry,  and  if  possible,  porous 
and  of  a loamy  nature.  A very  sandy  soil  is  useless.  Ashes  are  entirely' 
satisfactory  for  this  purpose.  Authorities  on  the  subject  of  sanitation 


Sanitation  and  Sewage  Disposal  for  Country  Homes.  59 


recommend  the  “Dry  Closet”  rather  than  the  “Privy  Vault,”  because  it  is 
far  more  sanitary  and  becomes  less  of  a nuisance. 

Regarding  earth  closets,  Gerhard  states  the  following  in  the  annual 
report  of  the  State  Board  of  Health  of  Maine: 

“All  that  is  needed  is  a common  closet,  a supply  of  dry  earth,  a water 
tight  receptacle  beneath,  and  a convenient  way  of  disposing  of  its  con- 
tents at  quite  frequent  intervals.  The  receptacle  should  be  wholly  above 
the  ground,  and  may  consist  of  a metallic  lined  box,  or  half  of  a kerosene 
barrel  with  handles  on  it  for  removal,  or  better  still,  a galvanized  iron  pail. 
The  receptacle  may  be  removed  through  a door  in  the  back  of  the  closet 
or  in  front  of  the  seat,  or  by  having  the  seat  hinged  and  made  to  open 
backward  it  may  be  removed  in  that  way. 

“The  earth  used  should  be  common  garden  or  field  loam  finely  pul- 
verized. Road  dirt  does  well,  but  sand  is  not  suitable.  Coal  ashes  are 
also  good.  Whichever  is  used  should  be  dry  and  screened  through  a sieve 
with  about  one-fourth  inch  meshes.  The  dry  earth  may  be  kept  in  a box 
set  where  it  can  be  filled  from  the  outside  of  the  closet,  or  it  is  quite  con- 
venient to  have  one-half  of  the  seat  hinged,  and  beneath  it  a small  com- 
partment to  hold  the  supply  of  earth.  In  this  box  there  may  be  a small 
tin  scoop  which  may  be  used  for  sprinkling  over  the  refuse  a pint  or  more 
of  earth  each  time  the  closet  is  used.  The  main  thing  is  to  use  enough 
earth  to  completely  absorb  all  liquids.  This  last  requirement  of  course 
precludes  the  throwing  of  slops  into  the  closet.” 

A CONCRETE  SLOP  WATER  DISPOSAL  BASIN. 

The  Tank. — Fig.  1 shows  an  arrangement  for  the  disposal  of  slop  water 
from  the  kitchen  or  laundry.  In  many  farm  houses  where  it  is  imprac- 
ticable to  install  a complete  sewage  system,  such  a convenience  as  the 
concrete  basin  shown  will  greatly  reduce  the  labor  of  disposing  of  house 
slops.  It  is  entirely  sanitary,  and  may  be  used  satisfactorily  either  winter 
or  summer. 

The  basin  tank  for  receiving  the  slops  is  made  of  concrete.  The 
mixture  should  be  in  the  proportion  of  1:2:4,  that  is,  one  part  of  cement, 


FIG.  1. 


Slop  Water  Disposal  Basin. 

two  parts  of  sand,  and  four  parts  of  broken  stone.  The  thickness  of  the 


60  Missouri  Engineering  Experiment  Station/Bulletin  3. 

walls  should  be  four  inches.  The  side  walls  should  be  vertical  and  the 
bottom  should  slope  with  a one-inch  fall  toward  the  center. 

The  size  of  the  tank  is  18"  wide  x 18"  long  x 18"  deep.  A three-inch 
inlet  pipe  connects  the  tank  to  the  kitchen  sink  or  laundry.  To  aid  in  the 
escape  of  offensive  gases  from  the  tank  the  wooden  cover  is  perforated 
with  several  holes.  This  does  not  entirely  prevent  the  escape  of  gases 
through  the  opening  of  the  sink,  but  if  the  tank  and  pipes  are  flushed 
occasionally  little  difficulty  will  arise  from  the  escape  of  gas  through  the 
sink  into  the  house. 

A four-inch  discharge  pipe  connects  the  tank  to  a ditch  located  at  a 
distance  not  less  than  from  fifty  to  one  hundred  feet  from  the  house. 

In  case  the  ditch  cannot  be  given  sufficient  slope  for  readily  discharg- 
ing the  waste  matter  as  it  comes  from  the  concrete  tank  it  will  be  better 
to  use  the  subsurface  or  underground  method  of  disposal  which  will  be 
described  later. 

The  wooden  cover  is  hinged  as  shown  to  a 2"  x 4"  piece  of  wood 
which  is  bolted  to  the  concrete  in  a manner  as  indicated  in  the  drawing. 
The  cover  rests  on  a concrete  projection  at  the  side,  and  for  convenience 
in  opening,  a ring  is  attached.  A strainer  should  be  provided  in  the  bottom 
of  the  tank  as  shown  in  Fig.  1.  This  strainer  is  to  prevent  the  entrance 
of  solid  matter  into  the  discharge  pipe  which  might  thus  become  choked. 

Construction. — Excavate  to  a depth  of  two  feet  below  the  ground  sur- 
face. The  finished  size  of  the  excavation  is  to  be  2'-2"  wide  x 2'-2" 
long  x 2'  deep.  Locate  the  inlet  and  the  outlet  pipes  according  to  the 
measurements  indicated  on  the  drawing,  Fig.  1,  giving  each  pipe  sufficient 
fall  to  provide  for  a ready  drainage  of  the  slop.  Use  the  earth  as  one 
side  of  the  form,  the  other  side  of  the  form  being  constructed  of  one-inch 
lumber  properly  braced.  First  lay  the  side  walls,  and  after  about  thirty- 
six  hours  remove  the  forms.  Then  lay  the  concrete  in  the  bottom  and 
carefully  plaster  the  inside  throughout.  If  crushed  rock  cannot  be  had, 
creek  sand  and  gravel  may  be  used  with  entirely  satisfactory  results.  The 
concrete  should  be  rammed  into  place. 

Disposal  of  the  Outflow. — The  discharge  from  the  above  slop  basin 
may  be  emptied  directly  into  a running  stream,  or  into  a ditch  some  fifty 
to  one  hundred  feet  from  the  house.  It  will  soon  be  purified  and  no 
offensive  odors  will  form  from  it.  The  respective  sizes  of  the  inlet  and 
discharge  pipes  should  be  three  inches  and  four  inches.  They  should  be 
vitrified  clay  pipe  with  cemented  joints.  The  slop  tank  should  be  fifteen 
to  twenty  feet  from  the  house.  The  slope  of  the  inlet  pipe  should  be 
greater  than  the  slope  of  the  outlet  pipe.  A slope  of  one  foot  in  fifty  feet 
for  the  outlet  pipe  is  desirable  in  order  that  it  may  be  cleansed  by  the 
velocity  of  flow. 

Subsurface  Disposal  of  the  Waste. — It  is  not  possible  in  every  case 
to  dispose  of  the  waste  water  as  explained  above.  Should  the  ground  be 
very  flat,  no  ditch  being  available,  other  methods  of  disposal  must  be  re- 
sorted to;  chief  among  them  being  subsurface  irrigation  or  disposal.  In  a 
subsurface  disposal  system  a 3"  open-jointed  drain  tile  is  used,  laid  with 
J4  to  5^  inch  open  joints,  and  to  a slope  of  one  inch  in  twenty-five  feet. 
It  is  very  essential  that  the  tile  be  laid  to  a uniform  slope.  If  possible  the 
ditch  should  be  excavated  eight  to  twelve  inches  below  the  pipe  and  filled 
with  sand,  gravel,  cinders,  or  other  porous  material,  to  aid  in  the  imme1 
diate  filtration  of  the  waste  water. 


Sanitation  and  Sewage  Disposal  for  Country  Homes.  61 

The  tile  should  be  laid  from  eight  to  twelve  inches  below  the  surface 
of  the  ground.  It  is  essential  that  the  drain  tile  be  as  near  the  surface  of 
the  ground  as  possible  in  order  that  the  waste  water  may  be  purified  by 
the  oxygen  which  is  present  in  the  surface  layers  of  the  earth.  At  a 
greater  depth  this  purifying  process  is  greatly  retarded  due  to  the  absence 
of  oxygen.  Should  the  ground  be  of  a compact  or  clay  nature,  a greater 
length  of  drain  tile  will  be  necessary,  as  also  there  will  be  greater  need 
for  the  porous  material  beneath  the  tile. 

The  approximate  cost  of  such  a slop  water  disposal  system  is  given 
below.  If  the  waste  water  is  emptied  into  a ditch  or  running  stream  the 
cost  of  slop  basin  will  be  $5.85  as  shown  below.  If  the  subsurface  disposal 
scheme  is  used,  then  an  addtional  50  feet  of  3"  pipe  drain  tile  will  be  re- 
quired. Fifty  feet  of  drain  tile  at  three  cents  per  foot  will  add  $1.50  to 


the  cost,  making  a total  cost  of'  $7.35. 

Approximate  Cost — Labor  not  Included. 

Cement,  two  sacks  at  40c $ .80 

Hinges  25 

Ring  10 

Sixty-five  feet  of  vitrified  clay  pipe  at  6c 3.90 

Wooden  cover  25 

4"  elbow  35 

3"  elbow  30 


Total  $5.85 


CESSPOOLS. 

The  general  definition  of  a cesspool  is  a tank  into  which  the  house 
sewage  is  discharged,  said  tank  retaining  the  solid  and  sometimes  the  liquid 
matter  until  removed.  There  are  two  types  of  cesspools,  viz.,  leaching  and 
tight  cesspools. 

The  leaching  cesspool  is  built  of  loose  brick  or  stone  without  the  use 
of  cement  or  mortar.  Through  the  crevices  in  the  side  of  the  cesspool  the 
liquids  leach  out  into  the  surrounding  soil  leaving  the  solid  matter  to 
remain  in  the  cesspool  until  removed  by  pumping  or  by  similar  means. 

The  tight  cesspool  is  built  of  brick  or  concrete,  it  being  essential  that 
the  cesspool  be  water  tight.  The  liquid  is  removed  by  being  drained  out 
through  a drain  pipe.  The  solids  are  removed  as  in  the  leaching  cesspool. 

The  writer  quotes  from  the  following  authorities  in  regard  to  the 
unsanitary  conditions  of  cesspools. 

“Sparkling  water  may  not  be  pure.  It  may  contain  typhoid  germs. 
The  filtration  of  sewage  effluent  does  not  purify  it  although  it  may  clarify 
it.  It  requires  the  action  of  oxygen  and  light  to  render  sewage  harmless.” 
— Burton  T.  Ashley. 

“It  is  hopeless  to  depend  upon  the  purifying  influence  of  intervening 
soil  to  protect  the  wells  from  cesspool  fouling,  because  soil  filtration,  in 
order  to  be  effective  must  be  intermittent.” — Mason. 

“The  cesspool  is  a relic  of  medieval  shiftlessness  and  carelessness  for 
which  no  excuse  can  be  offered.” — Dr.  Bashore. 

“The  privy  or  cesspool  is  walled  with  loose  stone  so  that  the  liquid 
waste  may  leak  through  them  into  the  surrounding  soil.  The  result  of  this 
is  a gradual  increasing  pollution  of  the  soil  and  often  a neighboring  spring 
or  well  becomes  so  contaminated  as  to  spread  disease.” — Prof.  Merriman. 


62  Missouri  Engineering  Experiment  Station,  Bulletin  3. 


THE  SEPTIC  TANK. 

The  modern  septic  tank,  sometimes  called  a scum  tank  or  putrefaction 
tank,  consists  essentially  of  a water  tight  chamber  of  suitable  capacity, 
through  which  the  sewage  flows  slowly,  and  almost  continuously,  the  inlets 
and  outlets  being  submerged  to  prevent  an  undue  disturbance  of  the  surface 
scum. 

Countless  numbers  of  bacteria  harbored  in  the  surface  scum  and  living 
upon  the  solids  in  the  sewage,  cause  its  liquefaction.  All  solids  settle  to 
the  bottom  of  the  tank  from  which  they  are  removed  at  frequent  intervals. 

Septic  Tank  Effluents. — While  the  liquid  waste  from  the  septic  tank 
contains  but  little  solid  matter,  it  is  highly  charged  with  putrescible  matter 
in  solution,  and  the  liquid  gives  off  bad  odors,  particularly  on  warm  or 
damp  days.  It  cannot  be  sufficiently  emphasized  that  the  septic  tank  pro- 
cess is  only  a preliminary  process  of  sewage  treatment,  that  the  waste  from 
septic  tanks  are  neither  clarified,  nor  purified,  that  they  contain  all  the 
dissolved  organic  substances  which  are  the  chief  causes  of  contamination 
of  lakes  and  streams,  and  that  a further  purification  in  most  cases  is  neces- 
sary. 

Operation  of  Septic  Tanks. — No  septic  tank  shows  good  results  when 
first  put  in  operation.  It  is  necessary  that  the  process  be  carried  on  for 
several  weeks  before  it  becomes  efficient.  The  claims  that  all  suspended 
impurities  are  liquefied  and  that  there  will  be  no  increase  in  the  deposit  of 
solids  or  in  the  scum  in  a septic  tank  have  not  been  realized.  On  an  average 
only  from  thirty  to  fifty  per  cent  of  the  suspended  solid  matter  is  destroyed, 
partly  by  liquefaction  and  partly  by  changing  them  into  gas. 

Capacity  of  Septic  Tanks. — The  capacity  of  the  septic  tank  should  be 
made  in  size  about  three-fourths  the  daily  volume  of  the  sewage.  Otherwise 
the  tank  acts  as  a mere  settling  chamber.  On  the  other  hand  the  tank 
should  not  be  too  large,  as  the  sewage  remains  too  long  in  the  tank.  By 
the  use  of  two  tanks  in  series  the  capacity  of  each  tank  may  be  reduced. 

Open  and  Closed  Septic  Tanks. — For  isolated  buildings  it  is  preferable 
to  use  covered  tanks,  notwithstanding  the  fact  that  open  tanks  have  been 
found  to  be  quite  satisfactory.  Reasons  for  this  are:  that  bad  odors  are 
confined  within  the  tank;  the  sewage  scum  is  concealed  from  sight;  the 
surface  of  the  sewage  in  the  tank  is  protected  from  wind,  rain  and  snow; 
but  most  important  of  all,  the  probable  infection  of  food  in  the  house  by 
flies  is  prevented. 

Small  Concrete  Septic  Tank. — Fig.  2 shows  a concrete  septic  tank 
which  is  designed  large  enough  to  provide  for  the  sewage  disposal  of  a 
family  of  six. 

The  tank  operates  as  follows:  Sewage  enters  tank  ‘A”  through  a four- 

inch  inlet  pipe  from  the  house.  A heavy  scum  will  form  over  the  surface 
of  the  liquid,  and  beneath  this  scum  the  sewage  is  liquefied  by  the  action 
of  the  bacteria  which  develop  or  grow  in  the  surface  stum.  For  the  suc- 
cessful growth  or  culture  of  these  bacteria,  the  scum  must  not  be  frequently 
broken  or  disturbed,  hence  the  inlet  pipe  is  made  to  discharge  below  the 
surface  of  the  liquid.  For  the  same  reason  the  overflow  pipe  from  tank 
“A”  to  tank  “B”  is  extended  below  the  surface  to  about  the  middle  of  tank 
“A”  where  the  liquefaction  of  the  sewage  is  most  complete. 

In  the  sludge  discharge  pipe  provision  is  made  for  cleaning  out  the 
sludge  from  the  settling  tank  without  putting  it  out  of  service,  and,  further- 


Sanitation  and  Sewage  Disposal  for  Country  Homes.  63 

more,  provision  is  made  for  the  discharge  of  the  contents  of  the  tank  during 
a time  when  it  may  be  found  necessary  to  repair  the  siphon. 

After  passing  through  the  flush  tank  the  sewage  may  be  discharged 
directly  into  a creek  or  a running  stream.  Under  most  conditions,  if  a 
running  stream  were  not  available,  the  effluent  may  be  discharged  into  a 
ditch  or  other  drainage  branch  which  should  be  seventy-five  or  one  hundred 
yards  from  the  house.  No  offense  from  odor  will  ordinarily  be  given  from 
such  a system  of  disposal,  as  there  will  usually  be  enough  rain  during  the 
year  to  flush  the  small  creek  or  ditch  into  which  the  waste  enters. 

FIG.  2. 


Small  Concrete  Septic  Tank. 


When  the  effluent  is  discharged  direct  into  a running  stream  of  sufficient 
flow  the  tank  “B”  may  be  omitted.  If  the  waste  is  treated  by  subsurface 
irrigation,  then  the  flush  tank  “B”  should  always  be  used  in  order  to  have 
the  sewage  delivered  intermittently.  If  the  flow  be  continuous  upon  the 
ground  then  sufficient  time  is  not  given  to  allow  the  air  to  enter  the  soil, 
and  consequently  it  soon  becomes  water-logged. 

A six-inch  partition  should  separate  settling  tank  “A”  from  flush  tank 
“B.”  The  liquefied  sewage  flows  from  tank  “A”  from  flush  from  which 
it  is  removed  by  means  of  an  automatic  siphon,  which  is  so  designed  that 
it  will  discharge  when  the  sewage  reaches  a certain  height  in  the  flush  tank. 
This  siphon  should  be  so  arranged  that  it  will  discharge  the  liquid  twice 
every  twenty-four  hours.  This  siphon  action  will  take  place  when  the 
tank  is  receiving  a flow  of  three  hundred  and  sixty  gallons  per  day. 

To  provide  for  the  entrance  of  air  into  tank  “B,”  which  is  necessary 
for  the  successful  operation  of  the  siphon,  and  also  to  provide  for  an  over- 
flow of  the  sewage  in  case  the  siphon  becomes  clogged  and  refuses  to  dis- 
charge the  contents  of  tank  “B”,  an  overflow  pipe  is  connected  to  the  main 
discharge  pipe  as  shown  in  Fig.  2. 

A valve  is  placed  in  the  bottom  of  the  flush  tank  “B”  to  provide  for 


64  Missouri  Engineering  Experiment  Station,  Bulletin  3. 

the  removal  of  sediment  which  in  time  may  collect  there. 

The  cost  of  the  above  septic  tank,  not  including  labor,  is  as  follows: 


Cement,  22  sacks  at  40c  per  sack $ 8.80 

175  ft.,  4"  V.  C.  pipe  at  8c  per  foot 14.00 

10  ft.,  3"  V.  C.  pipe  at  6c  per  foot 60 

Automatic  siphon  15.00 

Incidentals  5.00 


Total  $43.40 


As  will  be  noted  above  no  estimate  of  the  cost  of  sand  or  gravel  has 
been  made.  In  most  farming  communities  this  may  be  obtained  from  creeks 
or  branches  nearby  at  the  expense  of  hauling. 

SUBSURFACE  DISPOSAL  OF  SEWAGE. 

In  septic  tank  disposal  sewage  systems,  as  in  all  others  of  whatever 
nature  they  may  be,  some  provision  must  be  made  for  the  effluent  after  it 
leaves  the  tank.  If  it  is  allowed  to  flow  out  upon  the  ground  continually 
a nuisance  will  soon  be  created,  which  may  endanger  health.  In  the  absence 
of  running  streams  into  which  to  empty  it,  some  other  means  of  disposal 
must  be  resorted  to.  Perhaps  the  one  of  universal  application  is  the  sub- 
surface disposal  scheme.  This  plan  may  be  successfully  used  whether  the 
ground  be  level  or  sloping.  In  fact  it  is  about  the  only  method  that  may 
be  used  in  a flat  country. 

Subsurface  disposal  means  the  disposal  of  the  liquid  sewage  through 
a system  of  open-jointed  drain  tile  laid  from  eight  to  twelve  inches  below 
the  surface  of  the  ground.  The  open  joints  should  be  from  one-fourth  to 
one-half  inch  apart,  covered  with  some  material  to  prevent  loose  earth 
from  falling  back  into  the  pipe  during  the  backfilling  of  the  ditch.  The 
length  of  the  drain  pipe  will  depend  upon  the  amount  of  sewage  and  char- 
acter of  the  soil.  An  intermittent  discharge  is  essential,  hence  the  necessity 
of  an  automatic  siphon.  For  the  lateral  drains  a three-inch  tile  is  ordinarily 
used. 

FIG.  3. 


Subsurface  Disposal  Plant. 


Sanitation  and  Sewage  Disposal  for  Country  Homes.  65 


It  is  evident  that  such  a system  of  disposal  requires  the  effluent  to  be 
a liquid,  otherwise  the  drain  tiles  would  soon  become  clogged  and  stop  the 
operation  of  the  plant. 

Design  of  the  Subsurface  Disposal  Plant. — Fig.  3 shows  the  arrange- 
ment of  a typical  subsurface  disposal  system.  The  plan  view  illustrates 
the  method  of  arranging  the  drain  tile.  The  distance  of  the  septic  tank 
from  the  house  is  about  one  hundred  feet,  and  from  the  septic  tank  to  the 
disposal  field  approximately  one  hundred  feet.  Local  conditions  will  govern 
entirely  as  to  the  location  of  the  tank  and  the  disposal  ground.  In  no  case 
should  the  tank  be  closer  to  the  house  than  one  hundred  feet. 

Construction. — The  pipe  connecting  the  septic  tank  to  the  house  should 
be  a four-inch  vitrified  clay  pipe,  with  bell  and  spigot  joints  carefully 
cemented.  The  four-inch  pipe  connecting  the  two  tanks  is  to  be  arranged 
as  shown  in  the  drawing,  Fig.  3. 

The  pipe  line  connecting  the  flush  tank  with  the  disposal  ground  is  to 
be  a four-inch  V.  C.  pipe  with  cemented  joints,  and  laid  to  a grade  of  at 
least  one-fourth  inch  to  the  foot. 

The  main  transverse  drain  tile  should  be  four  inches  in  diameter  laid 
level  with  cemented  joints.  It  is  necessary  that  this  tile  be  laid  level  in 
order  to  secure  an  equal  distribution  of  the  sewage  to  the  laterals.  The 
lateral  drains  should  be  three  inches  in  size,  laid  in  rows  about  fifty  feet 
long  and  eight  feet  apart,  and  laid  to  the  grade  of  one  inch  in  twenty-five 
feet. 

For  a family  of  six  people  from  150  to  200  feet  of  drain  tile  will  be 
necessary  in  a loose  soil.  In  a compact  clay  soil,  a much  greater  length 
will  be  needed,  probably  300  to  400  feet. 

Septic  Tank. — The  septic  tank  shown  here  consists  of  a settling  tank 
and  a flush  tank  provided  with  an  automatic  siphon.  For  the  details  of 
construction  see  Fig.  2. 

Approximate  Cost  of  Septic  Tank. 


Cement,  22  sacks  at  40c $ 8.80 

100  ft.  of  4"  V.  C.  pipe  at  8c 8.00 

10  ft.  of  3"  V.  C.  pipe  at  6c 60 

40  ft.  of  4"  drain  tile  at  4c 1.60 

150  ft.  of  3"  drain  tile  at  3c 4.00 

Automatic  siphon  15.00 

Incidentals  5.00 


Total  $43.00 


SURFACE  DISPOSAL  OF  SEWAGE. 

The  surface  disposal  problem  for  sewage  is  solved  in  various  ways. 
As  in  the  case  of  the  subsurface  disposal  scheme,  it  is  essential  that  the 
sewage  be  discharged  upon  the  surface  of  the  ground  intermittently.  Such 
an  arrangement  gives  time  for  the  purification  of  the  soil,  which  would  soon 
become  water-logged  if  the  flow  of  sewage  upon  it  were  continuous. 

Fig.  4 shows  a typical  surface  disposal  plant.  The  operation  of  the 
septic  tank  used  is  identical  with  that  of  Fig.  2,  the  only  change  being  in 
the  method  of  the  final  disposal  of  the  discharged  sewage.  See  Fig.  2 for 
the  details  of  the  construction  of  the  septic  tank, 


66  Missouri  Engineering  Experiment  Station,  Bulletin  3. 

The  Disposal  Field. — This  plot  of  ground  may  be  a small  patch  of  cul- 
tivated land  with  a growing  crop,  such  as  corn,  or  it  may  be  a piece  of 
meadow  or  pasture  land.  A plot  containing  2500  square  feet  will  be  ample 
to  take  care  of  the  sewage  from  a family  of  six.  This  plot  of  ground 
should  be  at  least  200  feet  from  the  house  or  well,  or  any  source  of  water 
supply.  Upon  reaching  the  disposal  field  the  sewage  empties  into  a ditch 
about  one  foot  wide  and  four  inches  deep  running  at  right  angles  to  the 
disposal  pipe  from  the  septic  tank. 

Distributing  Ditches. — The  distributing  ditches  may  be  from  four  feet 

FIG.  4. 


Surface  Disposal  Plant. 

to  six  feet  apart,  and  four  inches  deep  by  eight  inches  wide.  Their  length 
will  depend  upon  the  size  of  the  available  disposal  plot.  There  should  be 
a sufficient  number  of  ditches  to  quickly  and  equally  distribute  the  sewage 


over  the  field. 

Estimated  Cost. 

Cement,  22  sacks  at  40c $ 8.80 

100  ft.  V.  C.  pipe  at  8c 8.00 

10  ft.  V.  C.  pipe  at  6c 60 

Automatic  siphon  15.00 

Incidentals  5.00 


Total  $37.40 


DIRECT  DISPOSAL  SYSTEM. 

In  some  cases  it  may  be  advisable  to  dispose  of  the  sewage  directly 
into  a running  stream,  but  this  plan  is  not  to  be  generally  recommended  as 
the  best.  The  danger  is  that  the  water  farther  down  the  stream  sometimes 
used  for  drinking  purposes  may  become  contaminated,  or  the  supply  water 
for  stock  may  be  so  fouled  as  to  become  unfit  for  use.  If  the  flow  of  the 
stream  be  large,  the  dilution  will  be  so  great  that  little  danger  will  occur 
from  its  contamination  by  the  sewage  of  a single  farm  house.  Disease 


Sanitation  and  Sewage  Disposal  for  Country  Homes.  6 7 


germs  may  be  transmitted  for  a distance  of  several  miles,  hence  there  is 
always  danger  in  using  for  drinking  purposes  any  water  from  a river  into 
which  sewage  empties. 


Direct  Disposal  Plant. 


Fig.  5 shows  an  arrangement  for  the  disposal  of  sewage  direct  into  a 
stream.  The  discharge  pipe  should  have  a uniform  slope  of  about  one  foot 
in  twenty-five  feet  to  insure  its  proper  flushing. 

Estimating  the  Cost. — The  cost  will  obviously  depend  upon  the  distance 
of  the  house  from  a nearby  creek.  The  disposal  pipe  should  be  a four-inch 
vitrified  clay  pipe  and  will  cost  eight  cents  per  foot.  The  cost  may  be 
estimated  for  any  specific  design  in  hand  from  the  general  cost  data  given 
below,  including  cement,  sewer  pipe,  drain  tile,  and  concrete. 

Cement  40c  per  sack,  net. 

Sewer  pipe,  3",  6c  per  foot. 

Sewer  pipe,  4",  8c  per  foot. 

Sewer  pipe,  6",  11c  per  foot. 

Sewer  pipe,  8",  20c  per  foot. 

Elbows,  %>  and  1-16  bend. — 

3"  30c  each. 

4"  35c  each. 

6"  45c  each. 

8"  60c  each. 

Y’s  and  T’s. — 

3"  35c  each. 

4"  45c  each. 

6"  70c  each. 

8"  90c  each. 

Traps. — 

3"  65c  each. 

4"  75c  each. 

6"  $1.00  each. 

8"  $1.60  each. 


68  Missouri  Engineering  Experiment  Station,  Bulletin  3. 


Drain  Tile. — 

3"  3c  per  foot. 

4"  4c  per  foot. 

6"  6c  per  foot. 

Concrete. — On  an  average  concrete  for  the  above  construction  will  cost 
from  five  to  seven  dollars  per  yard  where  it  is  necessary  to  hire  all  labor 
and  buy  all  materials.  One  barrel  of  cement  (about  four  sacks)  will  in 
general  make  one  cubic  yard  of  concrete  consisting  of  a 1:2}4:5  mixture. 

PLUMBING. 

Fig.  6 shows  the  plumbing  of  the  bath-room,  kitchen  and  laundry  ot 
a modern  house.  The  plumbing  necessary  for  carrying  the  sewage  to  the 
main  sewer  outside  of  the  house  is  also  shown  in  the  drawing.  It  will  be 
noted  that  the  system  is  fully  vented  so  that  no  trouble  will  be  had  from 
the  escape  of  sewer  gas  into  the  house. 

The  fixtures  usually  placed  in  the  bath-room  are  the  bath  tub,  wash 
basin,  and  the  water  closet;  in  the  kitchen,  a sink,  and  in  the  basement  a 
laundry  tray  or  tub. 

The  main  ventilation  or  soil  pipe,  as  it  is  commonly  called,  should  pass 
upward  through  the  roof  to  the  open  air.  Its  purpose  is  to  relieve  the  gas 
pressure  which  might  otherwise  force  the  traps  and  enter  the  house.  The 
top  of  the  soil  pipe  should  be  covered  with  a cap  to  prevent  the  entrance 
of  rain  or  snow. 


FIG.  6. 


70  Missouri  Engineering  Experiment  Station,  Bulletin  3. 

Cost. — The  cost  of  the  plumbing  will  depend  upon  the  quality  of  the 
fixtures  installed.  For  a two-story  seven-room  house  fitted  with  first-class 
plumbing  and  fixtures  throughout,  the  cost  will  be  about  $165.  This  cost 
item  includes  the  following:  Bath  tub,  wash  basin,  water  closet,  kitchen 

sink,  laundry  tub,  a forty  gallon  hot  water  heater  in  the  kitchen,  all  the 
necessary  water  piping  to  bath  room,  laundry  and  kitchen,  and  all  the 
necessary  drain  tile  and  sewer  pipe  completely  installed  ready  to  connect 
with  the  main  sewer  located  outside  a few  feet  away  from  the  house. 

The  expense  item  of  $165  mentioned  above  includes  the  cost  of  both 
labor  and  material.  We  may  add  to  this  sum  $50  for  the  septic  tank  and 
sewer  pipe  outside  of  the  house,  giving  a total  cost  of  $215.  This  estimate 
does  not  include  the  cost  of  a supply  tank  for  water,  nor  the  cost  of  putting 
in  the  water  supply  pipes.  The  water  supply  is  described  in  a bulletin: 
“Water  Supply  for  Country  Homes,”  which  may  be  obtained  by  addressing 
the  Director,  Missouri  Engineering  Experiment  Station,  Columbia,  Missouri. 


